import React, { Component } from 'react'

export default class Count extends Component {

  state = { carName: '奔驰c63' }

  // 加法
  increment = () => {
    const { value } = this.selectNumber
    this.props.jia(value*1)
  }

  // 减法
  decrement = () => {
    const { value } = this.selectNumber
    this.props.jian(value*1)
  }

  // 奇数再加
  incrementIfOdd = () => {
    const { value } = this.selectNumber
    if (this.props.count % 2 !== 0) {
      this.props.jia(value*1)
    }
  }

  // 异步加
  incrementAsync = () => {
    const { value } = this.selectNumber
    this.props.jiaAsync(value*1, 500)
  }

  render() {
    console.log(`UI组件接收到的props是，${JSON.stringify(this.props)}`)
    return (
      <div>
				<h1>当前求和为：{this.props.count}</h1>
				<select ref={e => this.selectNumber = e}>
					<option value="1">1</option>
					<option value="2">2</option>
					<option value="3">3</option>
				</select>&nbsp;
				<button onClick={this.increment}>+</button>&nbsp;
				<button onClick={this.decrement}>-</button>&nbsp;
				<button onClick={this.incrementIfOdd}>当前求和为奇数再加</button>&nbsp;
				<button onClick={this.incrementAsync}>异步加</button>&nbsp;
			</div>
    )
  }
}
